The goal of this Phase I SBIR research program is to develop a high-repetition-rate tunable IR laser system for high-throughput and high-sensitivity IR MALDI applications. Traditional MALDI had utilized low-repetition-rate laser systems, which can yield lengthy measurement times when large numbers of samples must be analyzed, or in cutting-edge scanning/mapping applications such as blot, direct gel or tissue analysis. Reducing analysis times is important for commercial high-volume laboratories in several areas including functional proteomics and drug discovery. Recent research has focused on utilizing high-repetition-rate (1 kHz) UV laser systems for both improved throughput and increased sensitivity in UV-MALDI and AP-MALDI experiments. However due to lack of suitable laser systems, there has been no research in the area of high-rep-rate IR MALDI, which has several advantages over UV MALDI including analysis of high-mass DNA and other high molecular weight biomolecules, analysis of biopolymers from gel blots or directly from cell or tissue samples, and the analysis of pharmaceuticals and other low molecular weight molecules (200 - 1500 Da). A tunable high-repetition-rate OPO laser system will be developed and built, and its MALDI performance for a variety of analytes will be assessed. [unreadable] [unreadable]